1. Field of the Invention
The present invention relates to a communication apparatus and, more particularly, to a communication apparatus for performing auto-redial processing for repetitively calling a distant station using a prestored call number until a connection is attained.
2. Related Background Art
Conventionally, in facsimile apparatuses, various data terminals, modem apparatuses, and the like, a so-called auto-dial function is known. With this function, a telephone number, which is stored in advance in association with a one-touch key or an abbreviated dialing operation, is automatically called according to a time measured by a timer or a predetermined key operation.
Furthermore, the auto-dial function often includes an auto-redial function. This function is used for repetitively calling a distant station using a stored telephone number until a response from the distant station is detected.
However, when a call instruction is input, the conventional auto-redial function always performs a redial operation a predetermined number of times until transmission is terminated even in the case of a false telephone number, in a line busy (or exchanger busy) state, or in a distant station busy state.
For this reason, calling operations can only be stopped after a dial operation of even a false telephone number is performed a predetermined number of times. When a person responds to the call at a distant station, he or she feels uneasy. In addition, since a line is wastefully held, communication cost is undesirably increased.
In a facsimile apparatus having an auto-dial function, when a calling party performs a calling operation using the auto-dial function, and a facsimile apparatus of a called party is set in a manual reception mode, if a response from an operator of the called party is delayed, the facsimile apparatus of the calling party cannot detect a facsimile communication procedure signal from the called party within an input signal monitor time (35 sec). As a result, a timer reaches a time-over state, and transmission cannot be performed.
As applications associated with a facsimile apparatus having an auto-dial function, U.S. Pat. Nos. 4,811,385 (issue date: Mar. 7, 1989), 4,910,506 (issue date: Mar. 20, 1990), and 4,641,133 (issue date: Feb. 3, 1987), and U.S. patent application Ser. No. 627,913 (application date: Dec. 17, 1990) are known.
However, there are no proposals that can solve the above-mentioned problems.